1. Field of the Invention
The present invention relates to light shutter devices, and more particularly to light shutter devices comprising chips of electrooptical material.
2. Description of the Related Art
Light shutter devices are known in which PLZT or like electrooptical material is used. The light shutter device comprises a chip prepared from an electrooptical material and having a plurality of shutter windows, and drive circuits for applying voltage to electrodes arranged in corresponding relation to the shutter windows. The chip and the drive circuits are bonded to a transparent substrate with an adhesive.
The light shutter device described has the problem that the adhesive present between the chip of electrooptical material and the transparent substrate influences the light to be transmitted through the device. More specifically, bubbles present in the adhesive give rise to the phenomenon of diffracting or refracting the light. Such bubbles become incorporated into the adhesive applied to the lower surface of the chip of electrooptical material when the chip is attached to the transparent substrate, and it is difficult to avoid this.
It therefore appears favorable to apply the adhesive to the chip except at the light transmitting region when the chip of electrooptical material is to be bonded to the transparent substrate. However, if the adhesive is thus applied locally, the thickness of the adhesive coating is liable to involve variations, which will tilt the chip. If the chip is tilted, light is refracted when passing through the chip, failing to reach the desired position.